Hands down my favorite airline there is. Southwest really is doing things right. Other airlines should take note. Their airlines are clean, tickets are reasonably priced, and they have a good rewards program. I also like the open seating. But what really takes the cake for me is their staff. One trip I was flying back home after tearing my ACL skiing, the staff was attentive in making sure I had a seat next to me to prop up my leg and that I had ice for my knee. Another time flying we were late flying out due to a crazy guy in the airport terminal and when I ordered a drink, the flight attendant said it was on him. Even when I pay for my own drink, I get some pretty good pours. They truly do everything they can to make your flight enjoyable.
Southwest, you have my heart and my business.